Lug cap



July 16, 1935. B, KRAMER 2,008,585

LUG CAP Filed June 25, 1931 ,0, IIIIIIII" ll Patented July 16, 1935 Eric B. Kramer,

Baltimore, M assignor to Crown Cork & Seal Company, In'ct, Baltimore, Md, a corporation of New York 51 i l i Application June 25, 193 1, Serial- No. 546,899

14 Claims. (atria-44) The present invention relates to caps or closures, and more particuarly to caps commonly known as lug caps for use on glass bottles and containers which have threads thereon, where- 5 by, upon rotation of the cap, the lugs will engage the threads and the container.

An object of the invention is to providea lug cap which has a stronger and more substantial 10 looking lug than caps of this type which'hav'e been heretofore used, and which-will, terefore, afford a greater sealing pressure. against "the mouth of a container.

Another object of the invention is to provide ii; a cap having lugs which will not tend to cut or scratch the threads upon the glass container with which the lugs engage to produce a sealing pres sure between the top of the cap and the mouth of the container.

A still further object of the invention is to provide a novel locking lug which may be formed with a minimum distortion of the metal, thereby avoiding mutilation of the cap decoration and weakening of the cap. a

The invention seeks to produce a lug which may be formed without substantial deformation of the cap skirt, and substantially without reduc ing' the depth of the skirt at any point. In the manufacture of lug caps it has been customary to utilize a blank which is substantially hat-shaped. The blank has a top, 3. depending skirt, and the free of the latter is formed into a flat flange extending at a right angle from-the skirt. This flange is ordinarily curled upwardly to form a head of circular form in cross section. By various operations upon this'bead it has been customary to form the same into lugs of various types and the present invention relates to an improved lug which overcomes the defectsof'lugs heretofore used.

The conventional type of lug has been formed by pressing the bead at intervals both inwardly and upwardly, so that the lugs formed are produced not only by an inward movement upon the bead, but by an upward pressure toward the top of the cap, the latter pressure collapsing the lug along axial lines, that is, lines extending toward the top of the cap or along the axis about whichthe cap is rotated when applying the same to the container. 1

Caps in which the head is axially collapsed have a lug with an inner edge which is relatively thin as compared to the remainder of the bead from which the lug is formed; consequent- 1y, they tend to cut or scratch the glassihreads securely ,lock the cap on of the container. Capsof this type are shown, for example in the patent to Hammer, No. 1,919,238, granted November 18, 1931, and in the patent to Hamm r, No. 1,440,940, granted January;2,1923.

The present invention contemplates a distinct departure from lugs of the type show in these patentsin that' the lug has an axial cross section orheight which is at least equal to, if not greater thamthe diameter of the bead. "I'his increasedheight of the lug along its inner surface provides a broad face which will not mar or cut theglass; it also increases the strength of the lugalongaxial, lines, i. e., in a direction away from the/top, along which the pressure is exerted as the cap is applied to a container.

Itrhas been suggested to form lugs by pressing the bead inwardly while maintaining the cross-sectional ,form of the bead, but it has been found that such lugs do not have the required strengthalong-axial lines, and do not properly engage the thread of a container. Lugs of this type are disclosed, for example, in the patent to Hammer, No; 1,440,984, granted January 2, 1923.

As distinguished from lug caps of the types above mentioned, the present invention contemplates'alug produced by radially inward pressure upon the bead, this pressure being applied so as to collapse the bead partially atleast, along radial lines, or, in other words, along lines ex- 3 tending at a right angleto the axis about which the cap is rotated when applied to a container. The axial cross section or diameter of the bead at a right angle to the cap radii, is not reduced, but is substantially maintained so that the strength of the portion of the bead forming the lug'is retained. Inthe preferred form of my invention this strength is increased by partially collapsing the bead along radial lines, thereby producing relatively straight vertical walls at the radially inner and outer sides of the lug.

The invention contemplates the formation of the locking lug substantially without appreciably reducing the depth of the skirt of the lugs, and,

consequently, with a minimum deformation of the-skirtat these points. This provides a lug having strength in the direction of sealing pressure;v i. e., at a substantial angle to the top of the cap... V V 1 It has been round from practical use of lugs of this-type that they do not tend to cut or scratch the glass. threads of a container, since their relatively broad radially inner surfaces, which preferably have'a height at least equal to the height of the remainder of the bead, afiord 5 compress the bead vertically or and at the same time to press the'beadinwardly.

' Since the caps are applied toglasscontainers so as to seal the same under considerable-pressure, it is obvious that modifications of this character which guard against scratching or cutting of the thread and provide lugs of increased strength are of great importance.

Another feature of the invention is the retention of substantially the full length or? depth of the skirt at the points where the lugs are formed. Heretofore it has been customary to shorten the skirt by a compression of the bead upwardly or substantially parallel to the axis of the cap. This reduction in depth of the skirt by vertical or axial compression not only weakens the cap where the lugs are formed,"but mentation and produce anunsightly cap. The

confining of the inward pressure upon the head to substantially radial lines retains substantially the full depth of the skirt, and by reducing the'deformation of the SkiIt PI'QVQIltS destruction of the ornamentationand'tends-to minimize rusting of the cap in use, aswell as tearing or cutting of the skirt in the manufacturing operation. It is preferable to exert the radial pressure which causes the radial collapsingand inward radial movement of the bead insuch a way that there is no substantial strain applied to the skirt above the lug; this will'avoid stretching'or thinning of the metal which would result from inward movement of the skirt above the bead. This is accomplished by permitting the. metal of the bead to flow upwardly in a direction which tends slightly to uncoil the bead with the result that the upper surface of the formed lug is produced "from'the material of the bead asdistinguished from the material of the skirtabove the head, the use of which would tend to' weaken the skirt by stretching themetal. i

In the accompanying a'pre'ferred embodiment this drawing,

Figure-i is a cross-sectional view. i

Figure 2 is a fragmentary bottom plan view taken at one of the lugs. v 1

Figure 3 is a sectional view on the'line 3-3 of Figure 2. V

Figure 4 is a fragmentary sectional view showing the formation of thebead before it is pressed inwardly to produce a-locking lug. a a

Figure 5 is a cross-sectional view; similar to FigureS. 'f

Figure 6 is a fragmentary perspective View of the outside of the cap. v e 3 Figure '7 is an inside perspective showing the lug formation;

Figure 8 is afragmentary sectional view of 'a slightly modified form of bead, and

Figure 9 lug formed from' a in Figure 8.

Heretofore it ha of the invention and in bead of thetype illustrated V i been customary. to collapse or along the skirt,

Or as an alternative, it has been proposed to press the bead radially inwardly while maintaining the circulargcross section;' The improved cap of the present invention retainssubstantially the full. depth of .theskirt .byp essing theibead formed by the metal .panying drawing, provided with a top H), and a depending skirt tends to destroy the ornadrawing mete is shown is a, cross-sectional view showing the radially inwardly without upward pressure or pressure along the axis about which the cap is turned when applied to a container, and at the same time the bead is partially collapsed or compressed along the same radial lines, or in the direction in which it is pressed inwardly. The inward pressure is applied in such a way as to permit the metal of the bead to flow in a direction tending to slightly uncoil the bead with the result that the top surface of the lug is of the bead and without inward movement or stretching of the metal of thefskirt above the head. V

This type of lug is illustrated in the accomwherein the cap is shown as l I, which is corrugated as at l2, the corrugations extending downwardly to a bead or curl, which is formed by rolling the lower edge of the skirt.

'The corrugations constitute means for gripping the cap when applying or removing the same, and also serve tostiffen the skirt and reinforce the lugs.

vThe outwardly curled lower edge forms a bead l3, and inthe present instance, the bead is formed by rolling the edge through three hundred and sixty degrees (360), thereby producing a closed head, best illustrated in Figs. 1 and a. The bead is of tubular form, and. preferably of circular cross section. A closedbeacl is preferab1e, since it prevents cutting of the hands and provides a cap in which the edge is concealed and protected against rusting. In additiomit provides a means from which the improved lugs ofthe present invention may be readily formed. To form the lugs the head is pressed. inwardly at intervals, and it will be understood that any desired number of lugs may be provided.

The inward pressure is applied along substan-.

tially radial lines so as to produce the lugs without shortening the skirt. Moreover, the pressure is preferably applied in such a way as to collapse the lug, partially at least, along the same radial lines, thereby producing from a bend of circular cross section (Figure 4) a lug of substantially' oval form, as shown in Figure 5. The lug I4 (Figure 5) has a radially inner surface l5, (Figure 2), which is substantially straight longitudinally of the lug, or, in other words, circumferentially of the skirt. Y

The inner surface l5 merges at its ends into short connecting portions ifia where the lug joins the remainder of the bead. This lug is formed by pressing the bead inwardly without deflecting any portion of the skirt which is corrugated; in other words, only the bead is pressed inwardly. Thus there is provided the longitudinally straight radially inner surface 15, which is also substantially straight along vertical or axial lines, thereby imparting considerable strength to the lugalong aXial lines indicated by the arrow Hi to meet the opposed pressure which is exerted against the top surface ll of each lug.

The top surface I! inclines outwardly from the top of the radially inner surface E5 to the skirt and joins the skirt immediately below the corrugations l2. Although the top surface of the lug inclines upwardly from the radially inner surface IE to the skirt (Figure 5), it is preferably of uniform height substantially from end to end of the lug. At the ends it of the lug this top surface sharply merges into the inner surface IQ of the bead.

Due to the longitudinally straigbt'or chordaocasss like formation of the radially ihneresurface i5,

it provides a support for thethread-ehgaging top surface H, and causes the latter to engage the thread through a considerable the length of the latter. Ithas been foundiu practical use of the 'capthat a lug of this forma- 4 and 5, does not appreciably reduce the diam eter at a right angle to'the radial diameter, or,

in other words, in the direction of the heightofj the skirt or along the axis of the cap.

- Thus there is provided the radially innersurface l5, which has a'height or axialdimension in the direction of the arrow I 6, at least-equal to": the axial diameter of the remainder'of the bead.

As will be evident from a comparisonof Figures- 4 and 5, the radially inward movement of the bead distorts the bead from its circular-form to the oval form of Figure 5, and the top surface :[1 is produced in substantially its entirety by an upward flow of the metal in the bead; -In other words, any given point A in the bead (Figure 4), when the latter is pressed inwardly to form the lug, moves upwardly, and in the completed lug assumes the position A indicated in Figure 5. This movement is permitted in forming the lug, the skirt being held against inward movement above the lug while the metal of the-bead isper mitted to flow in an upward direction. The top surface of the lug is thus formed almost entirely by the bead wall without inward movement or stretching of the skirt above the bead;

A lug of this character is to be distinguished from a lug which is formedby pressing the bot tom of the bead upwardly toward the top of the skirt. Such a lug is formed with a thino'r sharp radially inner surface which tends to cutfor scratch the glass thread upon the container-and weaken o-r mutilate the'same. At the same'time; the full depth of the skirtis maintained at the lugs with the result that the bottom surface-2B of the lug is even with or in substa'ntially'the plane of the remainder of the bead. Consequently, since there is substantially no axial pressure or resulting deformation of the skirt'in the direction of its depth, there is no t'endencyto mutilate any, ornamentation, or to deform" the skirt in such a way which would tend to tear the same in the manufacturing operation. I

The exterior of the bead (Figurefi), although slightly compressed, due to the inward movement of the outer surface 2 I' of the lug and the radial collapsing of the beadwhere the lug is formed, remains otherwise of the same appearance as the portion of the bead between thejseveral lugs. Hence there is provided a capof sightly construction with no deformation of the bead in a vertical direction or axially and 'a smooth deformation radially. i 3 v The radially innerand outer surfaces liand 2| of the lug have portions which are substan} tially straight along lines parallel to the axis of the cap in the direction of the arrow [6, and. thus' provide stronger and more rigid supports f'orthe top surface I! thanwould continuously" curved surfaces, and eflfectively resist deformation oftheluginuse'.

portion or to anoval form (Figurea), and the inward pressure along radiallines,

of Figure 4, except-"thet the bead is more com pletely closed by eurling'the free edge in excess degrees. (360),the edge 25 being carried downwardly to substantially the bottom ofthe bead, This bead whenp-r'essed of three hundredand sixtyiriwaiidly (Figure 9') to provide'a lug of theohar acter shown in Figure 6-, produces a lug of the same generalcross section, or, in other words, which is ova-l, as distinguished from the circular form from the remainder of thebea'd." -l3ut=the partial collapsing or compression of the bead ra-' dially brings the surfaces of the bead within the lug substantially into contact, due to the proi ision-of the three (3) plies 26, 21 "and 28. '"The lug is'thus-of solid form, as distinguished from the hollow form of Figure 5, and the three (3) substantially vertical plies arigid supportingmeans to oppose deformation of the lug in the use of the cap. 'I'his form of the invention differs from that of Figure marilyin the provision of a three-ply lug-as distinguished from a two ply lug, due to the'fact that the freeedge of the lug in Figure 9-isextended downwardlyto distinguished from the location of the same at the top of the coil, as in Figure 5. Moreoven the faces of the plies are substantially in contact, asdistinguished from the hollow lug of Figured =Asin the form of Figures 4 and 5',*the inward movement of the bead tends to cause a flow of the metal from the bead upwardly to produce the top surface, of the lug, tendency to slightly uncoil the bead, as will be evident'from a comparison of Figures 8 and-9; In the latter figure, it will be observed that the free edge of the bead within the coil has moved upwardly from its position in Figure 8' and a point A" on the inner surface (Figure 8), in the com 26, 21 and 28, aiford the flat inner surface l 5" and the inclined I l withthe bottom of the coil, as

and this flow results in a" Referring to Figure 8, there-isshowna Capra in'g a skirt" H and ahead #3 the latter being-of circularzformation and similar to the bead i3 Uponcomparing Figure5 withFigure 4, it will be noted that the bottom surface of the lug (Fig. 5) isslightly above illustrated in Figure 4, from which the lug (Figure 5) is formed. By comparing' Figure 9 with Figure 8, it will be observed that the bottom of the lug is slightly above'thebottom of the bead-(Figure 8') from which the lug is formed. But in thetwo forms there is no attempt to collapse along axial Iines'or reduce the depth of the skirt, and this reduction in depth, although small, is-necessarily incident "to the flow of the metal inapplying the strictly radialpres'sure, without attempting to stretch the metalof the skirt above the bead which would weaken the ski-rt and tend to tear the same in forming the'lug. the two forms itwill be understoodthat the entirelugis formed solelyfrom the bead substantially without utilizing any portion of the skirt above the bead. Thereby there is avoided weakeningof the metal in the skirt which would I result from'thinning or stretching the samein'an' efiort to form the top-of thelug by deflecting mwardlythe skirt above the bead;

the bottom surface of the bead tudinally straight inner chord-likesurfaces i5, l5, which support the top threadengaging surfaces l1, l1, and permit the thread of the container throughout a substantial portion of its length, which isnot possible when the lugs are provided with longitudinally convex radially inner surfaces. tion increases the strength of the lug by supplying a more extended support against downward pressure applied against the top, surface of the lug.

along the line of arrow l6. Whenthe hollow. lug formation of Figure 5 is somewhat preferable, due

to the fact that it provides a; resilient or cushion-- ing effect when the cap is applied to the container, this cushioning effect is of the character disclosed, and the-form of Figures 8 and 9 issatisfactory. Actual use of the cap shows that it may be applied readily with a positive gripping effect,- and-without cuttingof the glass thread. Although the cap may be readily removed, the lug is of such strength that it provides a tight seal between the liner and lip of the container without unduly deforming the lug. I 7

Although the invention has been described in detail, it will be understood that it is not limited to all features set forth in the drawing and in the foregoing description, of the several forms described may be made without departing from the invention.

Iclaim:- r V '1. A metal cap for containers comprising a top having a depending skirtprovided at its lower edge with a hollow bead,said bead being pressed radially inwardly at intervals and partially collapsed in the same direction to form lugs, each having a substantially longitudinally straight radially inner surface approximately equal in height to the diameter of the remainder of the bead. i

'2. A metal cap for containers comprising a top having, a depending, skirt provided at its lower edge with a hollow bead, said bead being pressed radially inwardly at intervals and partially collapsed in the, same directionto form lugs, the inner surface of each lug being substantially equal in height to the diameter of the remainder of the bead, and being substantially straight along lines forming a chord of the arc of the skirt.

3. A metal cap for containers comprising a top having a depending skirt provided at its lower edge with a tubular bead, said bead being pressed inwardly at intervals to form hollow lugs, each having an inner surface in height approximately equal in the diameter of the remainder of the bead, said surface formingrchords of the arc of the skirt, the bottoms of said lugs being insubstantially the plane of the bottom of the remainder of the bead whereby the skirt is of uniform depth throughout.

4. A metal cap for containers'comprising a top having a depending skirt'and provided at its lower edge with ahead, said bead being pressed inwardly at intervals to form lugs having bottoms in substantially the plane of the bottom of the V remainder of the bead, each lug having an inner surface which is substantially straight, circumferentially of the skirt and which has a height at least substantially equal to the diameter of the remainder of thebead. I v

5. A metal cap for containers comprising :a top having a depending skirt and provided at its lower edge with a bead, said bead being pressed inwardly along substantially radial lines at intervals to form lugshaving bottoms in substanlatter to engage the Moreover, this forma not. essential with a lug,

and that modifications being straight along lines aooaeezr tially the plane of the bottom of the remainder of the bead, each lug having an inner surface which is longitudinally straight circumferentially of the skirt.

6. A metal cap for containers comprising a top having a depending skirt and provided at itslower edge with a bead, said head being pressed inwardly along substantially radial lines at intervals to form lugs having bottoms in substantially the plane of the bottom of the remainder of the bead, each lug having an inner surface which is longitudinally straight circumferentially of the skirt along a line constituting a chord thereof, the part of the bead forming the lug being radially narrower than the remainder of the bead and at least the height of the bead.

'7. A metal capfor containers comprising a top i of the remainder of the bead, each lug having an inner surface which is straight longitudinally of the lug and circumferentially of the skirt, the part of the bead forming the lug being radially narrower 7 approximately the height of the bead.

8. A metal capfor containers comprising a top having a depending skirt and provided at its lower edge with a bead, said'bead beingpressed inwardly at intervals to form lugs having bottoms in substantially the plane of the bottom of the remainder of the an inner surface which is straight longitudinally of the lug and circumferentially of the skirt, the

top of each lug being rounded convexly toward the cap top longitudinally of the lug.

9. A metal cap for containers having a depending skirt provided at its lower edge with a bead pressed inwardly at intervals to form locking lugs, each lug having an innersurface which is straight longitudinally of the mg and circumferentially of the skirt and which in height is approximately equal to the diameter of the remainder of the bead l0. A metal cap for containers having a depending skirt provided at its lower edge with a tubular bead pressed radially inwardly and compressed in the same direction at intervals to form 11. A'metal cap for containers having a d epending skirt provided atits lower edge with a bead pressed inwardly at intervals to form looking lugs, each lug having a straight innersurface circumferentially of the skirt, the portion of the bead in each lug being of greater diameter axially of the cap than radially.

12. A metal cap for containers comprising a top having a depending skirt provided at its lower edge with a bead .of substantially circular form, said bead being pressed inwardly and partially flattenedalong substantially radial lines at intervals to form lugs having a substantially longitudinally straight inner face and a substantially oval cross-section of less diameter radially than the remainder of the bead and axially having a diameter about equal to the remainder of the bead. 1 13. A metal cap for containers comprising a top having a depending skirt provided at its lower edge with a bead ofsubstantially circular form, said bead being pressed inwardly and partially than the remainder of the bead and bead, each lug having flattened along substantially radial lines at intervals to form lugs having a substantially longitudinally straight inner face and a substantially oval cross-section of less diameter radially than the remainder of the bead and axially of about the same diameter as the remainder of the bead, each lug having its bottom surface in substantially the plane of the bottom of the remainder of the bead.

14. A metal cap for containers comprising a top having a depending skirt provided at its lower edge with a bead of substantially circular form, said bead being pressed inwardly and. partially flattened along substantially radial lines at intervals to form lugs having a substantially longitudinally straight inner face and a substantially oval cross-section of less diameter radially than the diameter of the bead and axially at least equal to the remainder of the bead, each lug having a radially inner surface about equal in height to the diameter of the remainder of the bead.

ERIC B. KRAMER. 

